The answer is yes digital can address analog coverage problems, but my experience, having done many analog-to-digital conversions, is that it almost always takes more transmitters to duplicate the coverage.

The problem is two-fold. First the digital pagers are generally not as sensitive as the analog pagers are for the initial alerting. Second, in poor coverage areas, users will hear the tone alert, which often can be detected by the pager at low signal levels, then they lift the pager off their belt to get the analog voice page. This significantly improves the receive performance of the pager.

With digital paging, the pager doesn't alert until after the message has been received. This means the signal levels have to be high enough for the pager to be alerted and reliably decode the digital paging message.

Joe Blaschka
President
ADCOMM Engineering

Editor:

In one area we solved the problem by obtaining a Part 22 paging frequency in VHF. The advantages are you can stay wideband, 500 watts effective radiated power (ERP) output and easy to simulcast without the cost of GPS and satellite receivers.

Find a paging carrier technician from the days of voice paging and they can engineer a paging/alerting system for much less than you mentioned in your article.

Art Gill
Anser-Quik Enterprises
Morehead City, NC

Editor:

While I agree that a privately owned digital paging network can meet both operational and compliance (ISO) issues, it is not necessarily the best economic choice. Alphanumeric paging is one-quarter century old technology and extremely limited in operational capability. Or, saying it another way, it is less than half a solution. Fortunately, there is a similar solution based on advanced digital paging technology that has two-way capability along with the ability to monitor and report assault, burglary, fire, robbery and emergency medical assistance.

The system infrastructure is no more expensive than the examples in your article. The difference is that two-way digital paging system can actually provide a payback by using a combination of technology and community planning. For example, digital paging addresses only the ability to notify personnel in times of need. Two-way digital paging allows a person with medical needs or a person being robbed or assaulted to use the same device to summon help. Calls from the two-way pager can be sent to others with two-way pagers or cell phones in the immediate area (business, governmental, institutional or residential) for instant response. The primary responders can directly summon EMS, fire, or law enforcement at the touch of a button. The use of two-way digital technology can actually reduce the number of emergency medical calls and false alarms by partnering with members of the community; a win-win proposition for all concerned.

A variation of the two-way digital pager is available for premise monitoring and notification. These devices can be directly connected to commercial alarm systems to provide direct notification to first responders. Case in point — rural churches are frequently targets of arsonists, thieves and vandals, along with fires caused by lightning, electrical malfunctions, etc. The personal and the fixed version of the two-way digital pager can send text messages directly to PCs, cell phones or other digital two-way devices. In a rural area, it is not uncommon to experience delays of up to a half hour when using a commercial alarm service, 9-1-1 and available first responders. With two-way digital technology, church officials, the local volunteer fire department and other local area responders can be alerted within 10 seconds or less.

Better yet, this technology may be eligible for Federal Emergency Management Agency (FEMA) grant funding under the Assistance to Firefighters Grant (AFG) program, which is open for submission of applications. The closing date for submission of grant applications ends Dec. 5. A free planner is available at http://info4u.us/NeighborNet.pdf.

Burch Falkner
Falcon Wireless
Birmingham, Alabama

Editor:

Why don't they consider talkback paging using handheld radios. The NEXEDGE protocol is perfect for this and it even works 100 percent on 6.25 kilohertz. The equipment is rugged enough, you can answer directly, and you do not need as many sites as if you used a TDMA system.

You are correct in that analog paging is most popular among fire departments here in the U.S. Many 9-1-1 administrators recognize the problems with analog/voice paging and are trying to persuade the fire chiefs within their jurisdiction to change from voice to alphanumeric paging, but these discussions are difficult and take time. A voice page takes about as long to send it as it takes to speak the message or about 10 – 15 seconds and to make matters worse, many of these voice paging systems have multiple transmitters that are not simulcast, so the message must be repeated off of each transmitter tower.

SONIK has been involved in many meetings with 9-1-1 administrators and fire chiefs across the country and these discussion can be very contentious, lengthy and difficult. But the benefits of digital paging should not be ignored.

Digital paging does inherently offer better RF coverage than analog paging. We have had discussions with some vendors who seem to think the opposite, but our tests over the past 10 years have proven that digital paging will offer better RF coverage than analog. So, it seems odd to us that, an announcement that digital paging may be the answer to the loss of RF coverage in analog paging system because of narrowbanding, seems to be newsworthy. It further surprises us to hear that, adding transmitters to a system design will improve in-building RF coverage, is also newsworthy. This is common sense, we have always thought, but is not common to most system designs, simply because of the increased cost involved and limited budgets of most public-safety agencies.

No doubt, if you increase the number of transmitter sites, you may be able to decrease the power output of each site, much like cellular systems, but even with lower power output, having to install a paging base station and antenna system at more sites, will increase the cost of the system.

Your article goes on to say: “Backhaul, either microwave or fiber, is not required for every site, reducing costs and giving fire departments more flexibility for site location. The architecture is also designed for better in-building coverage than analog. A traditional analog system uses less sites, but uses high towers. The digital system is similar to a cellular design with more sites closer to the ground for greater penetration."

SONIK has been providing paging systems for our customers for years, without the use of traditional backhaul, such as microwave or fiber. RF links and repeaters, while not common, have been around for years. We do this typically, when the customer does not already have microwave or fiber backhaul installed. Never does our customer install a microwave or fiber backhaul, to accommodate a new paging system. They either have it already for their trunked radio system, or they do not, so this issue does not impact the cost of the paging system, except that we now need to install RF links, which is what is proposed in your article anyway.

The system you refer to in your article was originally designed for mountainous areas of Europe, where transmitter sites are often geographically isolated, allowing for timing delay differences to each transmitter site, without the need for compensation. In the U.S., putting higher powered transmitters on high elevation sites has always been done to reduce cost. When there is an area where RF coverage is lacking, a fill-in transmitter is typically added to improve coverage in that particular area, so the whole system design is typically derived from a cost perspective. SONIK offers our paging systems with guaranteed RF coverage, based on pre-determined, acceptable building density penetration. We caution your readers about attacking the RF coverage issue from the perspective you suggest, as it will likely result in system costs that are over budget, or at least will require a higher budget to implement.

The main problem with fire departments’ use of voice paging is that it is so ingrained into their mode of operation, that they refuse to give it up. It made sense years ago, when conventional two-way radio systems were used for all two-way communications for the fire department. The Minitor pager from Motorola, with two channels, allowed fire personnel, especially volunteer firefighters, to monitor the main fire channel, without interfering with ongoing communications. It also allowed them to receive a page alert on the second channel. This was the perfect solution for fire departments that had a lot of volunteer fire fighters and they have gotten so used to this mode of operation, that they still demand it, even with the advent of trunked radio.

Trunked radio systems do not allow for easy monitoring of the main fire channel, with a Minitor pager, because the frequency being used for one conversation, is constantly changing. Some fire departments that we worked with have set up a patch through the dispatch console, which patches the trunked fire talk group through the dispatch console and transmits it out on a separate, conventional radio frequency, allowing the fire personnel, with Minitor pagers, to continue to monitor all fire communications. Even with the extra cost of setting up this conventional fire frequency, these fire departments felt it was worth it to be able to continue with their normal mode of operation, instead of making a change.

To help 9-1-1 agencies convert their fire departments to digital paging, SONIK developed a paging system that offers both analog/voice and digital/alphanumeric paging through the same paging system using the same transmitters. The transmitter will automatically switch from digital to analog mode, depending on which type of page is being sent out. This allows the 9-1-1 administrators time to show the fire chiefs the benefits of digital vs. analog paging. When a city or county is considering a voice only paging system upgrade and they find out they can get a combined analog and digital paging system for the same price, most of them are eager to consider it.

Digital paging is infinitely faster than analog, so that is the major issue. As you stated it in your article, when digital paging is integrated in CAD, the dispatcher can quickly accept CAD’s recommendations for dispatching an incident over the paging system by simply hitting the “send” button on his/her CAD screen. In an emergency, if you need to dispatch 100 voice pages and all are different, it will take the dispatcher at least 100 by 10 seconds, or 16.6 minutes. These same 100 alphanumeric pages will likely go out in less than a minute.

Cost of the pagers is another issue, not discussed in your article. A typical two-channel voice pager, such as a Minitor, sells for about $500. each. In contrast, a typical alphanumeric pager can be purchased for about $100 or one-fifth the cost. For a county with 300 or more pagers, that is a savings of about $120,000.

You can certainly purchase a paging system with more transmitters to improve in-building coverage, but we believe this approach is too broad and should be considered carefully. We believe you should attempt to design a system with as few transmitters as possible, to keep the cost down, then, with the proper propagation analysis tools, add transmitter sites as needed, to attain the desired RF coverage where you need it. This way, you are better able to keep costs down, vs. designing the entire system with a more low-powered transmitters from the beginning.

When you consider the demand for fire operations to remain as they have been for years, this change to digital can be a daunting task for 9-1-1 administrators. SONIK’s combined analog and digital paging system solution makes this an easier migration. And we can put in as many transmitters as you wish, using RF links, instead of microwave, if necessary.

Thanks for talking about paging, which is still a relevant communications system for many public-safety agencies.

Four years ago my company was asked to offer a solution for the data communications issues for fireguard service during emergency situations. We developed a multilink mobile broadband router utilizing several MNO networks at the same time and distributing traffic over these independent networks simultaneously.

This resulted in a very high up time, around 90 percent. But it couldn't solve connectivity issues in remote areas, and it was not a real success with real disasters where, while the smartphone became really popular around the same period and putting flicks on YouTube became popular, this behavior negatively influenced the available mobile broadband bandwidth. Putting spectators 3 miles away, into another cell, is not a practical solution for this issue.

Therefore we designed, with a specialized partner, a 3G amplifier that commits itself 100 percent to the 3G standard. This adaptive amplifier is totally invisible for operators, because it never offers too much energy at the cell towers. This turned out to be the missing link in this solution.

The router and the multilink 3G amp offered 100 percent connectivity rate in two months period, without even one second downtime, tested by an independent company interested in our technology to be deployed by themselves. This company handpicked 50 vans working in even the most remote areas, where they traditionally never succeeded to realize a reliable connection. Anyway lower than 5 percent connectivity rate. We changed that to 100 percent, their figures, not ours.

This solution also solved the bandwidth issue during emergency situations with many spectators. The 3G amps virtually increase cell sizes, on land, by a factor of two. Over water, even a factor of four. This enables the router to reach other cell towers during emergency situations where cell capacity issues arose. Everybody was happy.

In Europe there is a legal issue with the application of 3G amps. And since we now have developed a 5 band 4G amp, this legal issue is becoming more prominent. Right now we are working closely with the Department of Justice to solve this definitely.

During a recent visit with Vodafone Netherlands, I heard that until October, Vodafone has instructed the radio frequency authority to down 400 boosters. I estimate that in 10 months this authority would have had 1,000 requests, about 100 a month, to down boosters.

In the past three years we have sold about 300 3G amplifiers and about 50 4G amps. Not one customer has complained that our amps were asked to switch off and be turned over to this authority. All customers are happy, and the operators don't know about the existence.

Because of these broadband amps, we help governmental bodies to work better for much lower operational costs and mobile operators are not forced to more densely populate their cell structure for optimum coverage.

I think the article is quite outdated because we have done it already for four years successfully for a much lower price. We have expanded from fireguards to police. Now we expand to river and canal shipping inside Europe. Our customers have satellite domes on their vessels, but don't use it anymore.

One large dredging company from the Netherlands reached 22 kilometers at sea with Long Term Evolution (LTE) connectivity and is now completely overlooking its very small aperture terminal (VSAT) upgrade plans.

I'm a reader of Radio Resource International and I appreciate the valuable information that magazine provides me.

I've been really interested about public protection and disaster response (PPDR) and the relevant exploitation opportunities it offers to smart city and applicable technologies such as the information communications technology (ICT) area and software-defined radio (SDR).

This email aims to address the reasons why "Europe is the large unknown PPDR broadband spectrum territory" as you write in “Dispatch” of the Quarter 4 2014 issue of RadioResource International.

Available spectrum, spectrum sharing and network sharing are some of the main subjects addressed by the stakeholders, and at the end of their own analysis, always the economic limitations prompted a real stop to the chance to deploy a national private broadband network.

From the analysis of the U.S. strategy and from my personal experience and evaluation, I realized the only way to unleash the energy and motivations to get a common shared approach in Europe is to pragmatically define applicable and sustainable business models involving a stakeholder's area broader than the one currently limited into the classic PPDR.

The First Responder Network Authority (FirstNet) strategy is aiming to a real and pragmatic civil security-commercial interoperability. Maybe this the correct approach also for Europe? This is also the target of a specific working group managed by the European Telecommunications Standards Institute (ETSI) (see also SDR standardization mandate M512).

In the last years I've participated in working groups, European Union-funded programs, conferences and other events related to PPDR, and I've also published some papers on this subject. All efforts and sources of debate about the above matters are welcome. This is the subject I would appreciate to read in the 2015 issues.

On behalf of the 20 members of the Regional Wireless Cooperative (RWC) and other regional systems in Arizona, we are very pleased with the ruling by the FCC to eliminate the mandate to narrowband public- safety 700 MHz frequencies by January 2017. This now provides our member agencies sufficient time to transition infrastructure and their fleet of subscriber equipment at a pace that best suits their needs and their budgetary cycles. Additionally, allowing the local regional planning committees (RPCs) the authority to determine if and when narrowbanding is appropriate for their regions, best provides local input and control over this process based on local circumstances and needs.

We thank the commission for listening and responding appropriately to our concerns.

There are still a lot of issues with "mobile wireless" connections. Coverage in most localities is not universal. Dead spots mean that laptops (Wi-Fi, cellular, hot spots, etc.) may not live up to their full potential … and may fail when they are most needed.

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